Cache poisoning in React Server Component responses (CVE-2026-44576) | HOL Guard CVE

Medium severityCVE-2026-44576GHSA-WFC6-R584-VFW7

Cache poisoning in React Server Component responses

Answer in brief

CVE-2026-44576 records a Medium severity vulnerability in Cache poisoning in React Server Component responses. The current sources do not mark it as known exploited. The current feed maps next (npm), next (npm). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published May 6, 2026Updated May 7, 2026Source checked Aug 26, 2026First seen by HOL Aug 25, 2026Material review May 7, 2026

Upstream Advisory

Key facts

Risk: Medium
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps next (npm), next (npm). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
nextnpm	>=14.2.0<15.5.16	Not reported
nextnpm	>=16.0.0<16.2.5	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for next, next.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
May 6, 2026
Evidence: source:ghsa:source_dates:source-dates:record
Source modified
May 7, 2026
Evidence: source:ghsa:source_dates:source-dates:record
First seen by HOL
Aug 25, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

### Impact Applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML. ### Fix We now validate and interpret `RSC` request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL. ### Workarounds If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors `Vary`, or disable shared caching for affected App Router and RSC responses.

Quoted source text, attributed separately from HOL analysis.